Ecosystem Guidelines for Environmental Assessment

FRESHWATER
FRESHWATER
ECOSYSTEMS: WETLANDS
Liz Day and Nancy Job
INWARD-DRAINING (ENDORHEIC) WETLANDS - many of these receive water directly from precipitation
or groundwater seepage. The category is further divided into permanently and seasonally inundated
basins, and includes salt pans and reed and sedge pans
RIVERINE WETLANDS - including riparian fringes, seepage lines, floodplains and river source sponge areas
LACUSTRINE (LAKE-LIKE) WETLANDS - including coastal lakes, permanent and temporary freshwater
pans, blackwater lakelets
PALUSTRINE WETLANDS - including seasonal and permanent marshes and swamps, springs, sedge,
restio and reedbed marshes and Cape fynbos seasonal wetlands
ARTIFICIAL WETLANDS - including dammed or drowned basins within river catchments
ESTUARINE AND LAGOONAL WETLANDS - see Guideline 1, Coastal Ecosystems p.24
What are the key ecological “drivers” in terms of
maintaining ecosystem function, pattern or structure
Water quantity and flow regime, including surface and groundwater sources.
Water quality.
Geology and soil type and structure.
Biological processes, affecting biotope quality and availability.
What are the key challenges affecting management
General lack of knowledge as to how many systems function, their biodiversity and their links to other
systems.
Inadequate implementation of existing laws and policies aimed at protecting wetland resources and
ecosystems.
Integration of social / political and economic imperatives with ecological ones.
Maintenance of:
- natural or near-natural hydrological regime - including hydrological linkages throughout the
catchment and seasonal or permanent links with groundwater.
- natural or near-natural water quality.
- natural erosion and sedimentation processes.
- function - e.g. water quality amelioration; infiltration; floodwater retention, provision of low flows
to downstream users.
- maintenance of biological connectivity in the catchment and in the broader system - including
potential ecological linkages with terrestrial ecosystems (e.g. pollinators, seed dispersers).
- specific habitat quality and availability (genetic integrity, including biodiversity).
- maintenance of genetic integrity.
Co-ordination of management interventions at a catchment scale so as to maximise the potential for
achieving and sustaining all of the above objectives.
Integration of ecological and social objectives, so that improvement to one is not at the expense of
the other.
COLIN PATERSON-JONES
68 : FRESHWATER ECOSYSTEMS - WETLANDS